Disease and trauma affecting one or more articular surfaces of the knee joint are commonly treated by surgically replacing the end portions of the femur and tibia bones with prosthetic femoral and tibial implant components, and in some cases replacing the patella with a patella implant component. Such surgical procedures are often referred to as total knee replacement (TKR). In TKR surgeries, a surgeon typically affixes a pair of articulating prosthetic components to the patient's femur and tibia bone structures; namely, a femoral implant component affixed to the inferior end portion of the patient's femur bone and a tibial component affixed to the superior end portion of the patient's tibia bone.
Certain knee prostheses, including the knee prostheses illustrated and described in U.S. Pat. No. 7,326,252 to Otto et al., the contents of which are incorporated herein by reference, include femoral implant components having flexed or backdrafted interior surfaces that facilitate locking of the femoral implant component onto a resected inferior end portion of the femur bone. Interior surfaces of the femoral implant component, such as anterior and posterior interior surfaces, may converge or taper towards one another in a superior-inferior direction. These types of backdrafted femoral implant components can be installed onto the femur bone by at least slightly rotating the femoral implant component during axially displacement onto the resected end portion of the femur bone. In this manner, the femoral implant component is said to be “rolled on” the end portion of the resected femur bone to accommodate for the particular configuration of the component and to capture the resected end portion of the femur bone within an interior region of the femoral implant component.
Conventional femoral implant components, which have interior anterior and posterior surfaces that are arranged generally parallel to one another or which are slightly divergent in a superior-to-inferior direction, can be installed or impacted in a straight line onto the resected end portion of the femur bone generally along the anatomic axis of the femur bone. These conventional femoral implant components may utilize pegs or posts to further secure the femoral implant component on the resected end portion of the femur bone via insertion of the pegs into prepared holes pre-cut into the resected end portion of the femur bone. However, the above-discussed “roll on” installation procedure to install femoral implant components having backdrafted surfaces onto a resected end portion of the femur bone can hinder if not entirely prevent the use of conventional pegs or posts that are designed to be impacted in a straight line since the pegs or posts risk opening up or damaging the prepared holes and/or causing interference with the prepared holes as the femoral implant component is rolled onto the resected end portion of the femur bone.
Thus, there remains a need for providing orthopaedic implants with improved structures and mechanisms for anchoring, fastening, retaining, locking and/or fixation of components used in association with knee prostheses or other orthopaedic implants to the resected end portion of a bone, and methods for installing the orthopaedic implant onto the resected end portion of the bone. The present invention satisfies this need and provides other benefits and advantages in a novel and unobvious manner.